A sport having good, variable defence (7)
I believe the answer is:
apology
'defence' is the definition.
(I know that apology is a type of defence)
'a sport having good variable' is the wordplay.
I cannot really understand how this works, but
'a' is present in the answer.
'sport' could be 'polo' (polo is a kind of sport) and 'polo' is located in the answer.
'good' could be 'g' (abbreviation) and 'g' is located in the answer.
'variable' could be 'y' (algebra) and 'y' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for apology that I've seen before include "Poor substitute" , "bad example" , "Saying sorry; poor specimen" , "A poor example" , "Explanation for a fault" .)